1. Field of the Disclosure
The technology of the disclosure relates to wired and/or wireless communication systems employing a Radio-over-Fiber (RoF) communication system.
2. Technical Background
Wireless communication is rapidly growing, with ever-increasing demands for high-speed mobile data communication. As an example, so-called “wireless fidelity” or “WiFi” systems and wireless local area networks (WLANs) are being deployed in many different types of areas (e.g., coffee shops, airports, libraries, etc.). Wireless communication systems communicate with wireless devices called “clients,” which must reside within the wireless range or “cell coverage area” in order to communicate with an access point device.
One approach to deploying a wireless communication system involves the use of “picocells.” Picocells are radio-frequency (RF) coverage areas. Picocells can have a radius in the range from a few meters up to twenty meters as an example. Combining a number of access point devices creates an array of picocells that cover an area called a “picocellular coverage area.” Because the picocell covers a small area, there are typically only a few users (clients) per picocell. This allows for simultaneous high coverage quality and high data rates for the wireless system users, while minimizing the amount of RF bandwidth shared among the wireless system users. One advantage of picocells is the ability to wirelessly communicate with remotely located communication devices within the picocellular coverage area.
One type of wireless communication system for creating picocells is called a “Radio-over-Fiber (RoF)” wireless system. A RoF wireless system utilizes RF signals sent over optical fibers. Such systems include a head-end station optically coupled to a plurality of remote units. The remote units each include transponders that are coupled to the head-end station via an optical fiber link. The transponders in the remote units are transparent to the RF signals. The remote units simply convert incoming optical signals from the optical fiber link to electrical signals via optical-to-electrical (O/E) converters, which are then passed to the transponders. The transponders convert the electrical signals to electromagnetic signals via antennas coupled to the transponders in the remote units. The antennas also receive electromagnetic signals (i.e., electromagnetic radiation) from clients in the cell coverage area and convert the electromagnetic signals to electrical signals (i.e., electrical signals in wire). The remote units then convert the electrical signals to optical signals via electrical-to-optical (E/O) converters. The optical signals are then sent to the head-end station via the optical fiber link.
Wired and wireless peer-to-peer analog and digital communications are generally limited in range and coverage, respectively. Enhancing the range of wired peer-to-peer connections may require complicated amplifying and/or repeating requirements. Extending the coverage of wireless peer-to-peer connections typically requires a denser antenna deployment and/or transmitted power increase, which may be limited by government regulations, wireless standards, and battery peak power and energy storage considerations. In addition, extending the coverage may be prohibited by the use of proprietary protocols, such as medical equipment.